Saturday, 23 February 2013

Ecology:Arthrographis
is widespread, found in compost, decaying plant material and in the soil.

Pathology:Arthrographis
is generally considered to be a contaminant. Arthrographis kalrae has possibly been implicated in eye and
central nervous system infections as well as onychomycosis (nail
infections).A case of ethmoid sinusitis
has also been reported.Arthrographis cuboidea* has been
isolated from bronchial wash specimens however its pathogenicity remains
unsubstantiated.Other recognized
species are A.lignicola, A.pinicola, A.sulphurea and A.alba however they have yet to be implicated as human pathogens.

*Recent molecular study appears
to have reclassified this fungus, now known as Scytalidium cuboideum.I will
use the previous name throughout this post as I have found but a few references
to this change.

Physiology:Arthrographis
cuboidea exhibits relatively fast growth at 25 – 30oC, maturing
in about 3 to 5 days.It
grows equally well at 37oC at which temperature it may develop a
pink to lavender pigment on prolonged incubation, however it fails to grow at
45oCA.cuboidea possesses strong cellulolytic activity which can cause a
pink coloured ‘spalting’ in many species of hardwoods.

Arthrographis
kalrae exhibits slow growth between 25 - 30oC, maturing within 1
to 3 weeks. Growth may be enhanced at 37oC, perhaps giving it some
advantage as a human pathogen.A.kalrae
is capable of growing at 45oC which helps to distinguish it from A.cuboidea.A.kalrae is resistant to cycloheximide.

Macroscopic Morphology:(Species
dependant)

A.cuboidea –
rather fast growing as discussed above.Colonies are generally described as cottony to granular. Radial ridges or folds may develop.Colouration is white to pale yellow with a
yellow reverse.A pink to lavender
pigment may develop and diffuse into the media on prolonged incubation.

A.kalrae – is
initially glabrous, smooth and yeast-like.Colonies are slightly raised and become velvety or powdery as they
develop.Colour is described as a pale
yellow (cream) to yellow-buff to tan.The reverse is pale yellow to tan in colour.

Arthrographis species - SAB, 72 hrs at 30oC

Arthrographis species - Note no noticeable pink or lavender pigment on prolonged incubation.

Microscopic Morphology:Both species
produce hyaline, septate hyphae. Arthrographis species develop
conidiophores which differentiates this species fromGeotrichum & Scytalidium[i].Conidiophores are generally short and can be
branched or unbranched.The
arthroconidia which are produced from the conidiophores are smooth single
celled and hyaline.Arthroconidia
produced from the conidiophores are rectangular to cylindrical in shape and are
usually produced in chains.With A.cuboidea, arthroconidia formed from undifferentiated
hyphae are generally square or rectangular in shape.A.
kalrae may also produce lateral sessile (blastoconidia/aleuroconidia) which
may be submerged in the agar and difficult to discern.Intercalary arthroconidia may arise from
undifferentiated hyphae and are generally longer and narrower than those
produced from the conidiophores.Arthroconidia separate by fission through double septa.

Arthrographis species - hyphae bearing conidiophores from which chains of arthroconidia extend.(LPCB, X400)

Arthrographis species - as above but a closer look. The larger or somewhat 'swollen' structures (arrows), point to the conidiophores. Chains of arthroconidia are seen extending from the conidiophores. (LPCB, X400+10, DMD-108)

Arthrographis species - another look at the septate hyphae, conidiophors and chains of conidia. Note the 100 µm bar in upper right for scale.
(LPCB, X400)

Arthrographis species - Branched hyphae with conidiophores and chains of arthroconidia
(LPCB, X400+10)

Arthrographis species - intercalary conidophores, Chains of arthroconidia have collapsed around the tip. No, this is not a mixed culture. (LPCB, X400)

Arthrographis species - long chain of cylindrical or barrel shaped arthroconidia. Smaller, narrower conidia (intercalary?) seen bunched may be those produced from an undifferentiated hyphae discussed above. (LPCB, X 400+10)

Arthrographis species - one feature I haven't found mentioned in any of my resource material is the small lateral structure at the tip of the conidiophore. Any ideas?
(LPCB, X1000)

Arthrographis species - the curious structure found at the tip of the conidiophore.
(LPCB, X1000)

Arthrographis species - One last view of the curious lateral structure found at the tip of the conidophores of this particular species. I have not found mention of this structure in any of my resource material. (LPCB, X1000+10)

Note:I won’t venture a guess at what specific
species I’ve isolated here.Growth was
quite rapid and produced a pale yellow pigment favouring C.cuboidea.I did not
attempt temperature studies.While the
species survived on Dermasil™ media containing cycloheximide, growth was weak
and stunted.Only molecular studies would
provide the definitive identification.

[i] Recent
molecular study appears to have reclassified this fungus, now known as Scytalidium cuboideum.I have not found reference to this
reclassification nor how the presence or absence of conidiophores is
reconciled.

Saturday, 2 February 2013

While reading gastric biopsy gram preparations for Helicobacter
pylori, I came across this interesting gram negative helical bacterium. It
differed from the typical 'gull-winged' or wavy appearance characteristic of Helicobacter
pylori by having up to eight tightly wound spirals.Roughly double the size of Helicobacter
pylori, it ranges from about 3.5 to 8.0 μm in length and the spirals reach
an amplitude of about 1.0 μm.In my
career, this was only my third encounter with this organism, however morphology
alone immediately suggested the organism most likely was Helicobacter
heilmanii.

Some Background:

Helicobacter heilmanii was previously known as Gastrospirillum
hominis after first being described in 1987[i]. Though
figures in published literature vary, Helicobacter heilmanii appears to
be responsible for less than 1% of infections of the gastric mucosa.While Helicobacter pylori is transmitted
human to human, evidence suggests that Helicobacter heilmanii has an
animal reservoir and is probably acquired by close association with household
pets or farm animals.Children also may
be prone to infection by H.heilmanii due to closer contact with family
pets. This apparent 'zoonosis' also occurs more frequently in poorer
socio-economic settings.

Organisms which invade the gastric mucosa usually possess
the enzyme urease which can split the urea molecule into Ammonia (NH3)
and Carbon Dioxide (CO2).Tests have been developed which take advantage of this specific
reaction.With the CLOtest (Campylobacter
Like Organism test), a very small biopsy tissue sample is place
on the CLO media and allowed to react.If organisms possessing the urease enzyme are present in the tissue,
they will degrade the urea molecule as outlined above.The free CO2 dissipates however
the remaining ammonia will raise the media's pH with a resulting colour change;
with a negative, no colour change occurs.The alternative test is the C13 or C14 “Breath
Test” which utilizes urea labeled with one of the two isotopes of Carbon.
(Carbon-13 is preferential as it is non-radioactive).A base-line breath level is taken after which
the patient ingests a urea drink.If
bacteria are present which possess the urease enzyme, the urea molecule is split
into ammonia and carbon dioxide, however now the carbon dioxide is labeled with
the C13 isotope.It can be
distinguished from ambient carbon dioxide and the level obtained can be
compared to the base line.

Drawbacks;

Sensitivity and specificity of the CLOtest varies
significantly, with the product manufacturer claiming values of 98% & 97%
respectively (product insert), to another evaluation having determined values of
77% & 96% respectively[ii]. Our own
in-house evaluation generated even less optimistic values.

Regardless, both tests rely on the bacterium's ability to
metabolize the urea as well as the proper administration and interpretation of
the test[iv].It is unclear as to whether H.heilmanii
is as consistent and proficient as H.pylori in metabolizing urea and
these tests cannot distinguish between the two organisms.

Serological and immunohistochemical tests for H.pylori
are available however there is cross-reactivity with H.heilmanii. As such, current antibody tests also cannot distinguish
between the two species and there is no serological test specific to either.

Unlike H.pylori, H.heilmanii cannot be
cultured in the routine laboratory setting and no doubt would be time consuming
if a viable option.

Microscopic visualization remains the definitive test for
detection and identification of Helicobacter species in biopsy
specimens.

While concomitant infections with H.pylori and H.heilmanii
have been noted, they are exceedingly rare leading to unlikely speculation than
one may perhaps exclude the other.

Treatment for H.heilmanii is generally accepted to be
the same as for H.pylori; antibiotics and a proton pump inhibitor.I will not discuss specifics as I will leave
therapy to the physicians.My intent
with this post, as with all others, is simply to lay some groundwork for a few
pretty pictures.

Helicobacter heilmanii - Seen here in a gastric biopsy specimen (arrows). The spiral appearance is much more evident in the enlarged insert. The other large cells are gastric mucosal cells. As we are only examining the biopsy for Helicobacter (pylori), which is a gram negative organism, there is no advantage to doing a full gram stain. A small segment of the gastric mucosa, showing evidence of ulceration, was removed during an endoscopic procedure. This tissue was mashed up onto a glass microscope slide and stained with carbol fuchsin. (carbol fuchsin appears to stain these organism more intensely than gram safranin). My experience has been that these gastric organisms seem to occur in 'pockets' in that you may search a slide for quite some time and not see a single organism, then suddenly, bang! several or even many in one area. Pass over it and nothing once again.

(Nikon, Carbol Fuchsin Stain, X1000)

Heilicobacter heilmanii - from the same specimen as above. The resolution is better in this photo with the tight wavey spirals (upwards of 8 in number) quite evident. Organisms appear larger than above due to my cropping of the photograph.

(Nikon, Carbol Fuchsin Stain, X1000)

Helicobacter pylori - Compare the organism in the previous two photographs to Helicobacter pylori in this photo. The arrow in the inset photo points to just one H.pylori organism showing the curved "S" shape or "gull-wing" shape of the bacillus. Look carefully, the entire photo is teaming with H.pylori cells.

(Nikon, Carbol Fuchsin Stain, X1000)

Campylobacter jejuni - Compare the Helicobacter species in the previous photographs to Campylobacter sp in the one immediately above. Campylobacter also exhibits a curved or spiral (helical) morphology. In fact, Helicobacter pylori was initially called Campylobacter pylori. Here we can see a greater number of twists or spirals but there are not as many, nor are they as tightly wound as with H.heilmanii. While C.jejuni is usually isolated from fecal specimens, this photo shows the organism in a blood culture.

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About Me

Born in Hamilton Ontario Canada of Latvian parents, educated at The University of Western Ontario, (UWO)-London, Ontario
Met my wonderful American wife (Boston area) on a 1971 school trip to Quebec City.
Own registered company 'ThunderHouse Instruments' where I attempt to keep out of trouble making musical instruments, primarily Bass Guitars.
Earn a wage as a Medical Laboratory Technologist. Have worked in several Ontario hospitals. Involved in some Medical research with published papers.

Disclaimer

The information and photographs presented here were compiled for my own entertainment and should not be used as an absolute reference for medical and/or diagnostic purposes. Although I strive to ensure all information is accurate some errors or differences of interpretation may occur. Any errors mine alone. Fine text books, peer reviewed scientific papers and other internet references are available for detailed descriptions and analysis.

My intent here was simply to share some of the pretty pictures I've taken over the years.There is artistry and beauty in all of these organisms!

Enjoy!

Yuri

An Apology

My apology for the lame title of this Blog. My wife suggested I try 'Blogging' to pass the time while recuperating from a major illness. This entire endeavor started somewhat as a joke, my never intending to do much more. Put on the spot, I typed in "Fun With Microbiology - What's Buggin' You?" I now wish I could have thought of something clever and a bit more dignified.

Somehow it all got away from me and I find myself enslaved to the site, trying to find more and more interesting "photogenic" organisms to document.

Another apology appears elsewhere in this blog, however it is worth reiterating here. I apologize for the disproportional amount of fungal posts as this site should be about 'Microbiology'. As I had no original writing to contribute, I chose to share some photos which I had taken. While I would wish to have a somewhat equal balance of bacterial, mycobacterial & parasite posts, the majority of photogenic organisms that come my way are fungal.

I hope this blog site has evolved into a collection of photo-essays on organisms covered in a bit more detail than found at other sites or in most textbooks. I was always disappointed in the single photo depicting an organism as found in most textbooks. Microorganisms are fascinating creatures which exhibit diversity and cannot be summed up in a few short paragraphs or depicted with a single black & white photo tucked into the bottom corner of a page.

Microorganism are quite clever too - they have managed to evade our best efforts in being controlled for long or to be eradicated. As my prof once said "Microorganisms don't read textbooks so they don't know how they should behave."

Note:

Blogger's text editor has at times refused to accept the symbol μm for micron (Greek lower case letter for mu) when pasted directly from my Microsoft Word Program. Blogger's text editor converts my μm into mm (1000X larger). I have tried to catch and correct this wherever it occurs but the reader must be aware of the scale of structures described and apply the dimension intended. 1 μm = 1 Millionth of a Meter

Note on Agar Media Used

As a community hospital, we stocked only the most basic of mycological media.

The majority of plate photos are taken of cultures on Sabouraud Dextrose Agar which in our lab we refer to as SAB for short. Others my condense this to SDA. Please be aware that in this blog they refer to one and the same media. I apologize for any confusion.

Some photos may be from Mycosel™ of Dermasil™ selective agars while others may be from the nutritionally minimal Corn Meal Agar (CMA). The agar used will be stated when appropriate.

I would have liked to have used Potato Dextrose Agar (PDA) in some situations.

Microphotographs

All Micro photographs displayed on this blog were taken by myself except if noted otherwise.

Medical Technology Related Sites

Microbiology In Pictures

Please visit ‘Microbiology In Pictures’, a wonderful site created by Hans N. where you may be able to locate “Some pictures you may have been looking for but couldn't find...”

CMLTO

College Of Medical Laboratory Technologists of Ontario (Click To Redirect)

CSMLS

Canadian Society For Medical Laboratory Science

Mitchener Institute

Mitchener Institue

0SMT

Ontario Society of Medical Technologists

Health Canada

Center for Disease Control (Canada)

CSM

Canadian Society of Microbiologists

CDC

Center For Disease Control (U.S.A.)

CACMLE

Colorodo Association for Continuing Medical Laboratory Education

SAIT

Southern Alberta Institute of Technology

Wadsworth -New York State Dept. of Health

Mycology Critiques - Click to Redirect

University of Adelaide

Mycology Online -Click to Redirect

Mycology Online

An excellent Mycology site created by the University of Adelaide in Australia.They have a fantastic Glossary of Mycological Terms which can be accessed by clicking here.

Mount Sinai Mycology

Exellent Mycology Site from my colleauges at Mount Sinai (Click to Redirect)

U.W.O.

University of Western Ontario

Fungal Reference Books

Below is a list of fungal reference books I found of help in preparing this blog. Many other fine texts books and reference materials are available and the reader should decide what suits their own needs. For ease of locating these books or further information about them, I have added links to Amazon. I have no personal connection with Amazon and these books can no doubt be obtained through other sellers or their publishers.Note: Some prices through secondary sources are outrageous. Try the original publisher first and science libraries may carry these publications also.

While most of the fungi discussed in this blog are of clinical importance, some can be found in this publication.

Ash & Orihel’s Atlas of Human Parasitology

Click on Icon to redirct to Amazon

Ash & Orihel’s Atlas of Human Parasitology

An excellent, but rather expensive, reference book on Human Parasitology. Extensive photo gallery with short, concise text.Click on photo icon to redirect to Amazon.

Please Visit My Other Blogs

Tales From The Paddle - Short Stories based on my trips to the rivers of Northern Ontario, Canada (Click Icon To Redirect)

ThunderHouse Instruments - My workshop, where outside of the Microbiology Laboratory, I dabbled in making bass guitars amongst other instruments. (Click Icon To redirect)

Home, Sweet Home...

Contact Me - Mail

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Micro Mail

Okay, here it is. You can contact me via the icon above. I've reluctantly added it but may regret it. Call it an experiment.

I welcome any comments related to my posts, be it positive or constructive criticism. Please note that I probably will not respond to most comments as I barely have the time and energy to add new content to this blog.I absolutely will not offer to diagnose your ailment, be it that dry patch on your backside, that thingy you pulled out of your ear or that green stuff growing on the sides of your refrigerator! Please do not send me your photos for identification. I am not here to help you with your illness or your thesis! Finally, please realize, I am not a physician therefore I cannot offer medical advice.

New: I have not subscribed to the Linkedin service and if my profile appears there I am unaware of its origin. Please do not ask to be added to my non-existent Linkedin profile.

I freely share all my photographs on this blog site to all those who may find them interesting and useful. However, I do ask that you do not claim them as your own work, and give this site or myself credit when they are used publicly.

Nikon photographs are at 300 dpi while the DMD-108 defaults to 72 dpi which was ideal for web publishing. This resolution may be inadequate for print publishing however there is a web site entitled 'All About Digital Photos' which claims otherwise. Please keep this in mind if you request the use of my photos.

Please do let me know where and how you chose to use these photos as such feedback may assist me in deciding which posts to elaborate on or expand when I come across additional pertinent material.

A final note - I do not offer many sources or citations for the information offered in this blog. Most of the information can be found in commonly available textbooks, some of which I've listed in the sidebar above. More specific information can be found in peer reviewed papers & journals. I have tried to relay the content as accurately as possible, however, as the title of this blog implies, I do this for "fun". Have your own fun by conducting your own literature searches. Immerse yourself in microorganisms - you won't regret it!!